America, like much of industrialized society, is aging. The average of American is increasing and will continue to increase for the foreseeable future. There is every indication this trend will continue for at least the next several decades. One area of special concern is driving, an operation that requires a variety of physical and cognitive skills, many of which are known to change with age. In our society there is probably no document that is more highly valued by the older person than the license to drive. Yet, relatively little is known about the changing driving performance of older person, and even less is known concerning the effects on driving performance of the interaction of alcohol with aging. There is growing recognition that alcohol is more widely used in the older population than was previously recognized. Some of the symptoms previously attributed to the aging process itself now appear to be related, at least in part, to alcohol use in this age group. How alcohol interacts with aging to affect driving performance is largely unknown. Most states define 0.10% BAC as the legal definition of drunken driving, and in part because of this legal definition, many drivers believe that it is safe to drive at lower levels. However, it is known that impairment occurs at lower levels and that older persons may be more affected by a given amount of alcohol. There is also some suggestion that women may be at higher risk of crash at low levels of alcohol in comparison to men. In addition, very little is known about how alcohol interacts with sleep deprivation to affect driving performance. It is known that alcohol-related crashes are more likely to occur during nighttime hours, but both alcohol use and sleep deprivation are more likely to occur at these times. This project seeks to investigate systematically some of the key factors related to driving performance and measure how low levels of alcohol interact to affect performance. The overall objective is to examine the interrelationships among alcohol use, aging and driving performance. The specific aims of the project include: 1) to determine the effects of low levels of alcohol on driving performance as a function of age, gender, and driving complexity and more specifically: a) to determine the degree to which low levels of blood alcohol alter specific driving skills as a function of age; b) to examine how alcohol-aging effects on driving-related skills vary as a function of gender; c) to measure how alcohol-aging effects on driving-related skills vary as a function of driving complexity; and 2) to assess the alcohol-aging effects on driving performance as a function of sleep deprivation. The findings from this research should provide valuable information for counseling older persons regarding their alcohol use and driving and should clarify issues for further investigation.